Scaffold clamping device



Oct. 20, 1953 P. GRAY SCAFFOLD CLAMPING DEVICE 2 Sheets-Sheet 1 Filed D e c. 14, 1948 INVENTOR. fltww Oct. 20, 1953 'P. GRAY Filed Dec. 14, 1948 SCAFFOLD CLAMPING DEVICE 2 Sheets-Sheet 2 INVENTOR. fiaecr 62 y Patented Oct. 20, 1953 SCAFFOLD CLAMPING DEVICE Percy Gray, Richmond, Calif., assignor of onehalf to William Gray, Washington, D. 0. Application December 14, 1948, Serial No. 65,232.

2 Claims.

This invention relates to working stages or scaffolds used in various trades for supporting workmen at desired levels above the ground as in painting the side walls of buildings, and other operations requiring the safe support of one or more artisans above ground level. Scaffolds are also required in the work of paper hangers, lathers and other interior craftsmen forproviding convenient and dependable access to the upper portions of vertical walls and to ceilings. Whether the scaffold is supported from the ground level or is suspended from above depends chiefly upon the nature and requirements of the work being performed, both types being widely used. Since the load capacity of a scaffold should safely be such as to sustain as many workmen as can be accommodated thereon since it is not unlikely that at one time or another this situation will be encountered, the greatest attention in the past has been given to structural strength, Other factors are ready erection, adjustability to various levels when required, horizontal extensibility and compactness, both in the erected and in the dismantled condition.

While the foregoing conditions have been met in a reasonable degree by the prior art constructions and many of such have done so with desirable elimination of excess weight, there are other important requirements in a scaffold that have not, to my knowledge, been recognized or at least solved by such constructions. A prime requirement of a scaffold whether supported from the ground or suspended from above is easy extensibility of the horizontal stage without impairment of the inherent rigidity of the scaffold or deformation of its members. Maximum safety in a scaffold is accomplished by providing such inherent rigidity through a unitary immobile as sembly of the horizontal stage and the vertical supports for the same, thus not only providing a structure that is actually as strong as the components thereof, but is the safest in use'since workmen have at all times and under all conditions of use, complete confidence in the perfect functioning of the structure. To accomplish the foregoing with due regard for minimum overall weight dictates the use of wood or light metal at all but the points of joinder where excess stresses require the use of reinforced flange members of stronger metal such as steel. It is furthermore quite important that the scaffold design be such that it may be quickly erected and dismantled. The improved scaifold now to be described fulfills the foregoing requirements in an eminently satisfactory manner.

It is therefore a principal object of this invention to provide a new and improved scaffold or working stage.

Another object of the invention is to provide a scaifold in which the horizontal platform may be readily extended as desired without impairing its normal rigid connection with the vertical, side supports.

Another object of the invention is to provide a scaffold in which the working horizontal platform is rigid with the supporting side members under all conditions of use.

A further object of the invention is to provide a scaffold that is safe under all conditions of use due to the fact that the horizontal platform can not be dislodged from its anchorage with the side supports after its adjustment with respect thereto.

Another object of the invention is to provide a scaffold that may be readily adjusted to provide a horizontal working platform even when supported on uneven ground.

Another object of the invention is to provide a unitary and easily adjusted scaffold clamp for rigidly uniting the horizontal platform and one of the vertical, side supports.

A still further object is to provide a scaffold that is laterally quite stable in addition to its stability in the longitudinal directon of the horizontal stage. i

A still further object is to provide a scaffold clamp which serves to unite as an integral rigid unit a ladder member of usual type and conventional planking constituting the working platform thereof.

Another object is to provide av rigid scaffold assembly of end ladder member and working platform adapted for use with an ordinary ladder as the other end member thereof.

Another object of the invention is to provide a readily adjustable, rigid scaffold that may be adjusted or moved as required by a single workman.

The invention possesses other objects and advantages, some of which together with the foregoing, will be set forth in the following description of the preferred form of the invention which is illustrated in the drawings accompanying and form part of the specification. It is to be under.- stood, however, that variations in the showing made by the said drawings and description may be adapted within the scope of the invention as set forth in the claims.

Referring to the drawings:

Figure l is a perspective-view of one form of my improved scaffold,

Figure 2 is a plan view of the left end portion of Figure 1,

Figure 3 is an end elevation taken from the left of Figure 1,

Figure 4 is a perspective view of a preferred form of clamp member such as is also shown at the left of Figures 1, 2 and 3,

Figure 5 is a similar perspective view of the companion plain-p member shown also at the right of Figures 1, 2and 3,

Figure 6 is a perspective view of a modified form of clamp similar to that of Figure 4 but designed for use with a tubular formpf ,uertical support, and

Figure 7 is a modificationeofzthe form :of :clamp shown in Figure 4.

Reference is now made to Figure ,1 wherein it will be noted that the improved scaiTold of this invention comprises a pair of spaced, -vertical supports l suitably spaced from an identical hair of spaced avert cal u p s .2 an i idly t a horizontal stage or workin pla form 3 disposed therebetween. Thepairs of vert cal suppor s l, ;2 ma i e conveniently ref rr d to as zladders from their -general configuration, but as will later appear their function goes cons derably b yond the elementary use of ordinary ladders for the purpose of vertically supporting a -s aifiold. Each :such ladder is seen to comprise nair-ofunriehts I4 -andr5 of pr ferabl 'rectangular cross-section and provided with laterally extending footings 6 and 1, respectively, which prouide increasedzlateralstability since they extend consi,derably beyond the projected intersec- .tion of the u ri hts 1.6 and :1 are suitably :united t he u i h s by bolts -;8 {for exam e, one of each of whi h ls passes through an intermediate, diagonal Wedge nember 9 between 1 1 upri h and footing to in ure a m re sturdy union ofithese pa-rts.

e table members It of -wood or cnetaI having integral terminal connectors Il rbent angulrly o :form flan s overlying the sides of uprights A and 5 and permanently united thereto y riv t or b lts J2 se ve as p cer runes for I the uprights and are placed :near thejlower ends of the latter at a ipoint'below thezlowest operating :level of '1th ihori ontal platform :3. .Itwill be noted, howev r, v ii-ant cudarly.-.fr.om Fi ure Zithat such flanged connectors H are spacedpntwardly from th end surfaces of th vertical upri h 4 and -.5 so tha :.platform assembly can, :if desire e lowered p s thes :nungs hr u h the clea a ce spac rovided. ..A1so it :may be found desirable in vertical scaffolds of increased height to providerspacer runes t0 atinterralsfor the-entire'l gthofsuohuprieh s.

Th horizontl :platform 3 is composed oftwo series of inter-leaved, preferably rectangularly cro s-se tioned and elon atedimembers I53. Each series is ompos d f s ve al of such :Inem r t3 spaced apart the width of each intervening member and is united rigidly -to a pair of the uprights, 4, .5 byclamping means later to be described. At their terminal portions remote from such uprights each series is also united by one or more transversely extending steel strips M an 1.5 respectiv ly. desired fa t ning means such as olts .16 may be se t s cure the elongatedlmembers 13 to their respective steel strips. From the foregoing it will be apparent that each series of individual members is :moved toward the other as the -.pairs 10f uprights 4, 5 are .moved toward each other providing .a :horizontal platform of constantly intnneasing, 700D- ;with the ground. Footings tinuous central surface whose longitudinal extent depends on the spacing of the ladder members.

By uniting the horizontal stage 3 to the vertical supporting ladders l, 2 I have provided unique clamping means which insures a secure and rigid connection of these parts while one that is readily adjustable to the requirements pf the work. Attention is inyited-therefore to Figures 4 and 5*which show in perspective preferred forms of the component parts of such -clamp. In Figure 4 it will be noted that clamp 4-! ,includes a pair of generally triangular and horizontally disposed plates l8, l9 spaced one above :the other for a distance corresponding to the vertical thickness of elongated members it. .Rarallelism of ;.plates l8, I9 is insured by a vertically extending web portion joining the corresponding side legs of said triangular plates and a similar but shorter web portion 2! joining-the rend legs of said :plates. Web portion 2l eryes also a a supporting base for a pair of spaced, horizontally [disposed jaw m mbers 22 ,Whichare preferably united to said web portion by :means of n i t l b s rip 23 welded thereto. For enabling the clamp IT to beguided vertically on the upright 15 and rigidly iunlted thereto at yarious elevations, apair of vertically Spaced collars 2-4 shaped to closely surround the rectan ul r s ti d u r h exce f r a :narrow central area of the outer face thereof :for .a purpose later to be described.

icollars ,24 are vertically aligned .as is readily apparent from the drawing and are thus maintained andalso in fixedmelation with the previously described portions of clamp 151 by means of a central web portion 2,5 disposed flatwise a in t we portion 210 and unit d here o was .:by welding. z-Each web portion 2!!! is ;.provided with an inwardly extendin central tang .26 ad p d [press into the side of the adjacent elongated member .-,l.3 to anchor th same. Furthermore, each web portion .25 is :apertured :at a {point 25a disposed above the upper plate 1|;8 -:to meceive a locking pin r lt 2-1 Figure l) which proj through a selected 'one of a series of vertically ligned ap rtures .28 :in the hp ight 5 and may be s ured herein :by mean s ch as win :nut -2-9, for example.

In Fi re 5 ther :is shown .a persp t ve vi w a clam 5'15 de i ed speci i ally for coop ratio w th l mp 'll-l previousl deseribed to :rieidly connect horizontal stage 13 and end ladders I ndfl. Clamp 3511s generally the counterpart .of clamp II -1 and includes spaced, horizontal plates 36, '5"! corresponding to plates :18, [9, web portions 38 and 39 corresponding to Web portions 20 and 2|, vertically spaced collars 40 united "by a central web '52 and corresponding to collars 24 sepanated by'the web 25. An aperture 25b'is1ikewise provided in web portion 42 corresponding to aperture 25a of web portion '25. Instead of tang 26, however, the central portion of web 38 is bent inwardly ata right vangle toseryeasan abutment or stop for ashort member [3a {Figure ,1) which occupies the out rmost :po i ion (nearest the observer, Figure 1,). Also j,aw;members M corresponding to members .22 of Figure4 are formed as symmetrical ears centrally apertured to receive a hinge pin 45 journalling an anchor bolt 66 therein. The inwardly extending apex portions -4 of plates :36, 37 are upwardly and downwardly o'ifset where theyoverlie the corresponding portions of plates I8, 49 and each of such plates is provided with a vertically aligned aperture 48 for receiving locking means such as a bolt 49 secured in place by a wing nut 50, for example (Figures 1-3).

It will be noted from Figures 1 to 3 that short members 53a, identical with that referred to in the preceding paragraph are arranged alternately with the elongated members 13 to constitute with the latter members in effect, a solid block which may be drawn together by tightening of the wing nut 38a to anchor bolt 46 through the washer 5i, following which the bolt #9 may be inserted and wing nut 59 thereof, tightened.

It will be readily apparent that the clamp means just described for the ladder l is duplicated for the ladder 2. Also it will be clear from the foregoing that since the clamps are integral, rigid members, tightening of the fastening means thereof, i. e.: the wing nuts referred to, will insure an inherently rigid horizontal platform, vertical ladder assembly under all conditions of use and throughout all adjusted positions thereof.

In Figure 6 there is shown a form of clamp that is generally similar to the clamp depicted in Fig ure 4 and hereinbefore described with the difference that a tubular collar 53 suitably united to web portion 20 as by welding at 50 is substituted for the spaced collars 24 of the preferred form of the invention. Collar 53 is suitably apertured at 25a as has been previously described. For vertical ladders of tubular structural members it is advisable to provide rubber feet or cap members such as are indicated in dotted lines at 54 of Figure 6 to eliminate any possibility of marring floor surfaces when used interiorly as well as to insure against slippage.

In Figure '7 where is shown a modification of the preferred form of clamp permitting the use of ladder rungs a of usual type, that is, rungs that are wholly disposed within planes defined by the inner and outer surfaces of the vertical uprights. Such clamp differs from the Figure 4 construction in that the spaced collars 55 are disposed about the corresponding upright 5 as formerly but are rotated 180 from their former position before attachment as by welding at 56 to the web portion 29. For additional strength the collar portions nearest such web are not separated but extend continuously from their upper extremity to the lower extremity thereof.

As will readily be apparent from the foregoing, my scaffold may comprise the assembly of vertical end members and horizontal platform as shown in Figure 1 or it may, if desired, be confined to such platform and a single vertical end member, an ordinary ladder suitably united to the opposite end of such platform completing the same. Also, it is obvious that the improved form of integral clamp shown and described in the foregoing permits the use of planking of various widths as the platform thereof.

I claim:

1. A clamp for securing a scafiold platform to a pair of vertically disposed scaffold upright sup ports comprising a pair of members, each of which includes collar means substantially entirely circling one of said upright supports and releasably secured thereto, superimposed vertically spaced plates secured to said collar means, a web member connecting said plates along an edge thereof, said web member engaging a side portion of said platform and said plates engaging upper and lower surface portions thereof immediately adjacent said side portion, means on one of said members arranged to overlie a portion of the other member, means extending through the plates of each of said members and through the scaffold platform for releasably securing said platform and clamp together, and means mounted for horizontal pivotal movement on one of said members releasably engageable with a portion of the other member whereby said web members may be drawn towards each other.

2. A clamp for securing a scaffold platform to a pair of vertically disposed scaffold upright supports comprising a pair of members, each of which includes vertically spaced collar means substantially entirely circling one of said upright supports and releasably secured thereto, superimposed vertically spaced plates secured to said collar means and vertically spaced from the encircling portions thereof, a web member connecting said plates along an edge thereof, said web member engaging a side portion of said platform and said plates engaging upper and lower surface portions thereof immediately adjacent said side portion, means on at least one of said web members arranged to penetrate said side portion of the platform, cooperating overlapping means on said plates including registerable apertures whereby bolt means may releasably secure the same in fixed position, and horizontally extending bolt means for drawing said web members towards each other.

PERCY GRAY.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 350,153 Petty Oct. 5, 1886 405,195 Ayres June 11, 1839 412,989 Sixsmith Oct. 15, 1889 495,920 Strohm Apr. 18, 1893 574,486 Jones Jan. 5, 1897 714,761 Tilley Dec. 2, 1902 1,129,218 Macklem Feb. 23, 1915 1,218,144 White Mar. 6, 1917 1,312,994 Leonard Aug. 12, 1919 1,313,268 Cunningham Aug. 19, 1919 1,352,188 Giles Sept. 7, 1920 1,359,452 Walker NOV. 16, 1920 1,825,590 Hollister Sept. 29, 1931 2,300,018 Shuck Oct. 2'7, 1942 2,335,046 Droeger Nov. 23, 1943 

